Fundamentals of Air Traffic Control

Fundamentals of Air Traffic Control

Terminal and Enroute Radar By Crystal

History

Robert Alexander Watson-Watt (1892-1973), a descendant of James Watt, received a degree in Electrical Engineering from the University of St. Andrews, Scotland and in 1915 began a career in the British civil service, He patented his first radio location device, a device for locating atmospheric discharges, in 1919. In 1935, he received his eleventh radio-location patent, a device for detecting and locating an approaching aircraft. In the following years he was the leader of the intensive development of aircraft radio-location, the secret weapon of the Battle of Britain. In 1937, before the war began, Watson-Watt and his wife undertook the dangerous task of traveling disguised as ordinary tourists through Germany, searching for signs of German radar stations.

Theory and Fundamentals of Radar Operation

• Radar (radio detection and ranging)

• In 1888, Heinrich hertz demonstrated that radio waves were reflected by objects in the same manners light waves

Fundamentals of Radar

Components of Radar Systems

• Transmitter

• Antenna

• Receiver

• Indicator

Components of Radar Systems

• Transmitter– Creates high-powered radio pulses – Operates in UHF band or higher

– Radar pulse last about one microsecond

Components of Radar Systems

• Antenna– Antenna functions as both a transmitting and

receiving device– Pulses emitted by the transmitter are routed to

the antenna using a waveguide--a hollow metal channel that conducts the microwave energy to the antenna

Components of Radar Systems

• Receiver– Switched on as transmitter switches off– Upon receiving a reflection, the radar system

measures the time difference between the transmission and reception and uses this calculation to determine the objects distance from the antenna

– 12.36 microseconds is known as a radar-mile

Components of Radar Systems

• Indicator– Air traffic control uses a cathode ray tube

known as a plan position indicator (PPI) radar scope

Components of Radar Systems

• Indicator– Center of PPI known as the MAIN BANG

Components of Radar System

• Moving target indicator (MTI)– One way of eliminates ground clutter– Other way is to raise antenna a few degrees

– Check pages 309 - 314 of textbook

Types of ATC Radar

• Precision Approach Radar (PAR)

• Airport Surveillance Radar (ASR)

• Air Route Surveillance Radar (ARSR)

• Airport Surface Detection Equipment (ASDE)

Precision Approach Radar (PAR)

• Used primarily by the Department of Defense as a precision landing aid.

• Developed in the 1940’s• Before ILS

Precision Approach Radar (PAR)

• PAR consisted of a mobile facility thus making it most effective for the military

• Many PAR’s at airports were placed in the middle so that they could be turned

Precision Approach Radar (PAR)

Precision Approach Radar (PAR)

• PAR proved its effectiveness during the Berlin Airlift, landing aircraft every 90 seconds

• Some PAR’s still remain even though ILS is the landing air of choice

PAR Equipment (Inside)

PAR Antenna System MPN 13 Mobile System

New Stuff

Airport Surveillance Radar (ASR)

• Primary short range radar used by FAA

• Most major civilian airports use ASR

• Used in Approach and Departure Control Facility

• Range of about 100 Miles

Airport Surveillance Radar Antennas’

Air Route Surveillance Radar (ARSR)

• Long Range radar for Center use

• Have range of about 250 Miles

Old Center Radar

Center Radar Display

CO 123350CB757 310

Slide courtesy of Prof. J. Hansman

New Center Radar

En Route Full Data Block

AAL278330C068 500

Position Symbol

Beacon Target

AircraftIdentification

Ground Speed

Mode ‘C’ AltitudeX100

Leader Line

Computer Identification Number

Vector Line

Histories

Airport Surface Detection Equipment

• Short range radar system to help controller locate the locations of moving, ground based aircraft and vehicles

ASDE